They couldn't actually afford to have that happen because they then would have had to implement an accurate MAX specific simulator. Doing so would have revealed some of the other design flubs, such as the Flight Computer as a single point of failure. That's why they were so concerned about Lion Air setting a precedent for other customers with regard to simulators.

If there is one thing this entire saga has revealed, its that Boeing was criminally culpable at nearly every step of the way.

Starting with the design goals of the 737 Max, continuing with penny pinching during the implementation, then bullying and lying during the certification process, then further bullying during the sales and training process, then massive amounts of blame shifting after the first crash, trying to pin it on the airlines and the pilots, then repeating the same thing after the second crash, then not providing documentation and data during the investigation, then further trying to get away with half baked fixes, then bullying the FAA to try and allow the Maxes to fly well before they were ready, etc.

At every stage of the process Boeing has led with lies and bullying. There is absolutely no reason to give them the slightest of the benefit of the doubt.

For every action, the best approach is probably to consider what would be the worst thing Boeing could have done as a response, because that’s likely what they did.

And that is the true damning point: they wanted to hide a problem they were aware of, and maintain an illusion that all was fine despite knowing it wasn't. Had they taken a more neutral stance, they could argue they didn't know. Now it's just reckless stupid endangerment.